diff --git a/services/convert/pull.go b/services/convert/pull.go
index 7bee2b4c44..0cb4070595 100644
--- a/services/convert/pull.go
+++ b/services/convert/pull.go
@@ -66,31 +66,33 @@ func ToAPIPullRequest(ctx context.Context, pr *issues_model.PullRequest, doer *u
 	}
 
 	apiPullRequest := &api.PullRequest{
-		ID:             pr.ID,
-		URL:            pr.Issue.HTMLURL(),
-		Index:          pr.Index,
-		Poster:         apiIssue.Poster,
-		Title:          apiIssue.Title,
-		Body:           apiIssue.Body,
-		Labels:         apiIssue.Labels,
-		Milestone:      apiIssue.Milestone,
-		Assignee:       apiIssue.Assignee,
-		Assignees:      apiIssue.Assignees,
-		State:          apiIssue.State,
-		Draft:          pr.IsWorkInProgress(ctx),
-		IsLocked:       apiIssue.IsLocked,
-		Comments:       apiIssue.Comments,
-		ReviewComments: pr.GetReviewCommentsCount(ctx),
-		HTMLURL:        pr.Issue.HTMLURL(),
-		DiffURL:        pr.Issue.DiffURL(),
-		PatchURL:       pr.Issue.PatchURL(),
-		HasMerged:      pr.HasMerged,
-		MergeBase:      pr.MergeBase,
-		Mergeable:      pr.Mergeable(ctx),
-		Deadline:       apiIssue.Deadline,
-		Created:        pr.Issue.CreatedUnix.AsTimePtr(),
-		Updated:        pr.Issue.UpdatedUnix.AsTimePtr(),
-		PinOrder:       apiIssue.PinOrder,
+		ID:                      pr.ID,
+		URL:                     pr.Issue.HTMLURL(),
+		Index:                   pr.Index,
+		Poster:                  apiIssue.Poster,
+		Title:                   apiIssue.Title,
+		Body:                    apiIssue.Body,
+		Labels:                  apiIssue.Labels,
+		Milestone:               apiIssue.Milestone,
+		Assignee:                apiIssue.Assignee,
+		Assignees:               apiIssue.Assignees,
+		State:                   apiIssue.State,
+		Draft:                   pr.IsWorkInProgress(ctx),
+		IsLocked:                apiIssue.IsLocked,
+		Comments:                apiIssue.Comments,
+		ReviewComments:          pr.GetReviewCommentsCount(ctx),
+		HTMLURL:                 pr.Issue.HTMLURL(),
+		DiffURL:                 pr.Issue.DiffURL(),
+		PatchURL:                pr.Issue.PatchURL(),
+		HasMerged:               pr.HasMerged,
+		MergeBase:               pr.MergeBase,
+		Mergeable:               pr.Mergeable(ctx),
+		Deadline:                apiIssue.Deadline,
+		Created:                 pr.Issue.CreatedUnix.AsTimePtr(),
+		Updated:                 pr.Issue.UpdatedUnix.AsTimePtr(),
+		PinOrder:                apiIssue.PinOrder,
+		RequestedReviewers:      []*api.User{},
+		RequestedReviewersTeams: []*api.Team{},
 
 		AllowMaintainerEdit: pr.AllowMaintainerEdit,
 
diff --git a/tests/integration/api_repo_pulls_test.go b/tests/integration/api_repo_pulls_test.go
new file mode 100644
index 0000000000..aec492e65f
--- /dev/null
+++ b/tests/integration/api_repo_pulls_test.go
@@ -0,0 +1,34 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	repo_model "forgejo.org/models/repo"
+	"forgejo.org/models/unittest"
+	api "forgejo.org/modules/structs"
+	"forgejo.org/tests"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAPIRepoPulls(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	// repo = user2/repo1
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 1})
+
+	// issue id without assigned review member or review team
+	issueID := 5
+	req := NewRequest(t, "GET", fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d", repo.OwnerName, repo.Name, issueID))
+	res := MakeRequest(t, req, http.StatusOK)
+	var pr *api.PullRequest
+	DecodeJSON(t, res, &pr)
+
+	assert.NotNil(t, pr.RequestedReviewers)
+	assert.NotNil(t, pr.RequestedReviewersTeams)
+}